HS1A, King of Thailand, SK

The late King Bhumibol Adulyadej of Thailand, HS1A
(From RAST website)

King Bhumibol Adulyadej of Thailand, who held the amateur callsign HS1A, became a Silent Key in October at age 88 after a period of failing health. On the throne since 1946, he was the world's longest-reigning monarch and was the patron of the Radio Amateur Society of Thailand (RAST). 

According to the RAST website, "His Majesty the King had been presented the callsign HS1A by the Ministry of Communications at Chitrlada Palace on August 18, 1989 in a ceremony witnessed by RAST officers. Five years later, in November 1994, His Majesty placed RAST under his royal patronage." The website (http://www.qsl.net/rast/) also shows photos of the king using a handheld and the 1989 ceremony at which his callsign was presented.